Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
  • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
  • H01M50/409—Separators, membranes or diaphragms characterised by the material
  • H01M50/449—Separators, membranes or diaphragms characterised by the material having a layered structure
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
  • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
  • H01M50/489—Separators, membranes, diaphragms or spacing elements inside the cells, characterised by their physical properties, e.g. swelling degree, hydrophilicity or shut down properties
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B7/00—Layered products characterised by the relation between layers; Layered products characterised by the relative orientation of features between layers, or by the relative values of a measurable parameter between layers, i.e. products comprising layers having different physical, chemical or physicochemical properties; Layered products characterised by the interconnection of layers
  • B32B7/04—Interconnection of layers
  • B32B7/12—Interconnection of layers using interposed adhesives or interposed materials with bonding properties
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
  • H01G11/00—Hybrid capacitors, i.e. capacitors having different positive and negative electrodes; Electric double-layer [EDL] capacitors; Processes for the manufacture thereof or of parts thereof
  • H01G11/52—Separators
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
  • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
  • H01M50/409—Separators, membranes or diaphragms characterised by the material
  • H01M50/44—Fibrous material
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
  • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
  • H01M50/409—Separators, membranes or diaphragms characterised by the material
  • H01M50/443—Particulate material
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
  • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
  • H01M50/409—Separators, membranes or diaphragms characterised by the material
  • H01M50/449—Separators, membranes or diaphragms characterised by the material having a layered structure
  • H01M50/451—Separators, membranes or diaphragms characterised by the material having a layered structure comprising layers of only organic material and layers containing inorganic material
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
  • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
  • H01M50/409—Separators, membranes or diaphragms characterised by the material
  • H01M50/449—Separators, membranes or diaphragms characterised by the material having a layered structure
  • H01M50/457—Separators, membranes or diaphragms characterised by the material having a layered structure comprising three or more layers
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
  • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
  • H01M50/489—Separators, membranes, diaphragms or spacing elements inside the cells, characterised by their physical properties, e.g. swelling degree, hydrophilicity or shut down properties
  • H01M50/491—Porosity
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2457/00—Electrical equipment
  • B32B2457/10—Batteries
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
  • C09J2431/00—Presence of polyvinyl acetate
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
  • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
  • Y02E60/10—Energy storage using batteries

Definitions

• the present application relates to the field of secondary battery technologies, and in particular to a separator, a secondary battery, and an electrical apparatus.
• Secondary batteries due to the prominent characteristics of being lightweight and pollution-free, and having no memory effect, are widely applied in various types of consumer electronics and electric vehicles. With the continuous development of the new energy industry, users have put forward higher usage requirements for the reliability of secondary batteries.
• the present application provides a separator, aiming to improve the reliability of secondary batteries.
• the present application includes at least the following beneficial effects.
• the average fiber filament diameter in the first base film is 50 nm-550 nm, optionally 80 nm-350 nm.
• a ratio of a weight per unit area of the first base film to a weight per unit area of the second base film is greater than or equal to 1.02, optionally 1.2-2.5.
• the separator is enabled to better possess both heat resistance and strength, thereby further improving the reliability of the separator.
• the melting point of the first base film is 160 °C-370 °C, optionally 165 °C-330 °C; and/or the melting point of the second base film is 120 °C-265 °C, optionally 130 °C-230 °C.
• the thickness of the first base film is 2 ⁇ m-12 ⁇ m, optionally 3 ⁇ m-6 ⁇ m; and/or, the thickness of the second base film is 2 ⁇ m-9 ⁇ m, optionally 3 ⁇ m-5 ⁇ m.
• the battery can be enabled to possess good reliability while further increasing the energy density of the battery.
• a ratio of a porosity of the first base film to a porosity of the second base film is 1.05-3, optionally 1.1-1.5.
• the first base film exhibits higher porosity, providing better air permeability, while the second base film has lower porosity, delivering higher strength to provide a support function.
• the lamination of the first base film and the second base film can improve the reliability and cycling performance of the secondary battery.
• the ratio of the porosity of the first base film to the porosity of the second base film is 1.1-1.5, the air permeability and the supporting performance of the separator can be further balanced, thereby further improving the reliability and the cycling performance of the secondary battery.
• the porosity of the first base film is 30%-80%, optionally 50%-75%; and/or the porosity of the second base film is 30%-70%, optionally 40%-50%.
• the air permeability and the supporting performance of the separator can be further balanced, thereby further improving the reliability and the cycling performance of the secondary battery.
• the separator further includes an interlayer, where the interlayer is disposed between the first base film and the second base film, and the interlayer includes a binder; and optionally, the interlayer further includes filler particles.
• the interlayer is disposed between the first base film and the second base film, and the interlayer includes filler particles, the reliability of the secondary battery can be improved.
• the binder includes one or more of polyacrylate, acrylic acid, carboxymethyl cellulose, polyvinylidene fluoride-co-trichloroethylene copolymer, polymethyl methacrylate, polyvinylpyrrolidone, polyvinyl acetate, polyethylene-co-vinyl acetate copolymer, polyethylene oxide, polyarylate, cellulose acetate, cellulose acetate butyrate, cellulose acetate propionate, polyvinylidene fluoride, polyacrylonitrile, polyvinyl alcohol, starch, hydroxypropyl cellulose, regenerated cellulose, tetrafluoroethylene, polyethylene, polypropylene, and cyanoethyl pullulan.
• the binder in the interlayer includes the aforementioned components, the reliability of the secondary battery can be improved.
• the filler particles include at least one of inorganic particles, organic particles, and organic-metal framework materials.
• the filler particles in the interlayer can enable further improvement of the heat resistance and the strength of the separator, thereby improving the reliability of the secondary battery.
• the separator satisfies at least one of the following (1)-(3): (1) the weight per unit area of the separator is 5-20 g/m2, optionally 6-15 g/m2; (2) the porosity of the separator is 30%-55%, optionally 35%-45%; and (3) the air permeability of the separator is less than 350 s/100 cc, optionally 150 s/100 cc-300 s/100 cc.
• the present application provides a secondary battery, including the separator of any of the aforementioned schemes.
• the secondary battery employs the provided separator, the reliability of the secondary battery can be improved.
• the apparatus of the present application includes the secondary battery provided in the present application, it at least possesses the same advantages as the secondary battery.
• the average fiber filament diameter in the first base film 11 is 50 nm-550 nm, optionally 80 nm-350 nm.
• the average fiber filament diameter in the second base film 12 is 30 nm-450 nm, optionally 50 nm-260 nm.
• the average fiber filament diameter in the first base film 11 may be 30 nm, 44 nm, 75 nm, 80 nm, 93 nm, 100 nm, 116 nm, 135 nm, 160 nm, 188 nm, 204 nm, 255 nm, 288 nm, 300 nm, 326 nm, 350 nm, 397 nm, 400 nm, 420 nm, 450 nm, etc., or a range formed by any two of the aforementioned values, such as 50 nm-260 nm, 30 nm-44 nm, 75 nm-80 nm, 80 nm-93 nm, 100 nm-135 nm, 160 nm-188 nm, 204 nm-255 nm, 288 nm-300 nm, 326 nm-350 nm, 400 nm-450 nm, etc.
• the average fiber filament diameter of the base film has a meaning well-known in the art and can be tested using known devices and methods.
• a scanning electron microscope e.g., ZEISS Sigma 300
• SEM scanning electron microscope
• a plurality of test regions e.g., 5 areas
• a plurality of locations are selected using a scale for measurement, and the average value of the plurality of fiber filament diameters is calculated, which is defined as the average fiber filament diameter of the base film.
• a ratio of the weight per unit area of the first base film 11 to the weight per unit area of the second base film 12 is greater than or equal to 1.02, optionally 1.2-2.5.
• it may be 1.1, 1.11, 1.2, 1.3, 1.35, 1.4, 1.5, 1.65, 1.7, 1.8, 1.9, 2, 2.3, 2.5, 2.55, 2.6, 3, 3.5, 3.85, 4, 4.5, 5, 6, etc., or a range greater than or equal to any of the aforementioned values, such as ⁇ 1.1, ⁇ 1.11, ⁇ 1.2, ⁇ 1.35, ⁇ 1.5, ⁇ 1.8, ⁇ 2, ⁇ 2.5, ⁇ 3, ⁇ 3.85, ⁇ 4, ⁇ 5, ⁇ 6, etc., or a range formed by any two of the above values, such as 1.2-2.5,1.1-1.5, 1.65-1.9, 1.7-2.3, 2-2.55, 2.55-3, 2.6-3.5, etc.
• the weight per unit area of the first base film 11 is 2.5 g/m 2 -10 g/m 2 .
• it may be 2.5 g/m 2 , 3 g/m 2 , 3.5 g/m 2 , 5 g/m 2 , 7 g/m 2 , 8.1 g/m 2 , 9 g/m 2 , or 10 g/m 2 , or a range formed by any two of the aforementioned values, such as 2.5 g/m 2 -3 g/m 2 , 3 g/m 2 -5 g/m 2 , 3g/m 2 -7 g/m 2 , 5 g/m 2 -8.1 g/m 2 , 7 g/m 2 -10 g/m 2 , etc.
• the weight per unit area of the first base film 11 is 3g/m 2 -7g/m 2 .
• the weight per unit area of the second base film 12 is 2 g/m 2 -10 g/m 2 .
• it may be 2 g/m 2 , 2.5 g/m 2 , 3 g/m 2 , 5 g/m 2 , 6 g/m 2 , 8.1 g/m 2 , 9 g/m 2 , or 10 g/m 2 , or a range formed by any two of the aforementioned values, such as 2 g/m 2 -3 g/m 2 , 3 g/m 2 -5 g/m 2 , 2.5 g/m 2 -6g/m 2 , 5 g/m 2 -8.1 g/m 2 , 7 g/m 2 -10 g/m 2 , etc.
• the weight per unit area of the second base film 12 is 2.5g/m 2 -6g/m 2 .
• the separator is enabled to better possess both heat resistance and strength, thereby further improving the reliability of the separator.
• the weight per unit area of the base film has a meaning well-known in the art and can be tested using known devices and methods.
• the melting point of the first base film 11 is 160°C-370°C.
• it may be 160°C, 165°C, 170°C, 180°C, 196°C, 200°C, 225°C, 235°C, 245°C, 260°C, 280°C, 290°C, 300°C, 315°C, 320°C, 330°C, 350°C, 370°C, etc., or a range formed by any two of the aforementioned values, such as 160°C-170°C, 180°C-235°C, 225°C-280°C, 290°C-315°C, 350°C-370°C, etc.
• the melting points of the first base film and the second base film can be tested using devices and methods known in the art.
• differential scanning calorimetry may be used for measurement.
• the measurement may be performed in accordance with the following method: take 4-6 mg of the sample to be tested, place it in the sample chamber of a differential scanning calorimeter, and increase the temperature from 25°C to 400°C at a temperature rise rate of 10°C/min to obtain the melting endothermic curve of the sample, where the temperature corresponding to the peak of the curve is the melting point of the sample.
• the thickness of the first base film 11 is greater than or equal to the thickness of the second base film 12; and optionally, a ratio of the thickness of the first base film 11 to the thickness of the second base film 12 is 1.1-5.
• it may be 1.1, 1.2, 1.25, 1.3, 1.45, 1.5, 1.6, 1.75, 1.8, 1.9, 2.0, 2.15, 2.2, 2.3, 2.45, 2.5, 2.8, 3.0, 3.5, 4.0, 4.5, or 5.0, or a range formed by any two of the aforementioned values, such as 1.1-2.0, 1.6-2.15, 2.3-2.5, 2.8-3.5, 3-5, etc.
• the ratio of the thickness of the first base film 11 to the thickness of the second base film 12 is more preferably 1.5-3.0.
• the first base film and the second base film are selected from polyolefin materials.
• the thickness of the first base film 11 is 2 ⁇ m-12 ⁇ m.
• it may be 2 ⁇ m, 2.5 ⁇ m, 3 ⁇ m, 3.5 ⁇ m, 4.6 ⁇ m, 5 ⁇ m, 6 ⁇ m, 7 ⁇ m, 9 ⁇ m, 9.6 ⁇ m, 10 ⁇ m, 10.4 ⁇ m, 11 ⁇ m, 11.7 ⁇ m, or 12 ⁇ m, or a range formed by any two of the aforementioned values, such as 2 ⁇ m-2.5 ⁇ m, 2.5 ⁇ m-3 ⁇ m, 3 ⁇ m-4.6 ⁇ m, 5 ⁇ m-9 ⁇ m, 10 ⁇ m-11 ⁇ m, 11 ⁇ m-12 ⁇ m, etc.
• the thickness of the first base film 11 is optionally 3 ⁇ m-6 ⁇ m.
• the thickness of the second base film 12 is 2 ⁇ m-9 ⁇ m. For example, it may be 2 ⁇ m, 3 ⁇ m, 3.5 ⁇ m, 5 ⁇ m, 6 ⁇ m, 7 ⁇ m, 9 ⁇ m, etc., or it may be 2 ⁇ m-3.5 ⁇ m, 3 ⁇ m-5 ⁇ m, 5 ⁇ m-6 ⁇ m, 7 ⁇ m-9 ⁇ m, etc. In some embodiments, the thickness of the second base film 12 is optionally 3 ⁇ m-5 ⁇ m.
• the battery can be enabled to possess good reliability while further increasing the energy density of the battery.
• the thickness of the base film can be tested using devices and methods known in the art.
• a thickness gauge may be used to measure the thickness of the base film. Specifically, the following method may be adopted: take six groups of parallel samples, use a micrometer thickness gauge to measure the thicknesses of each group of samples at different positions, measure at least 20 points for each group of samples, and take the average value of the thicknesses of the six groups of samples as the thickness of the base film.
• a ratio of the porosity of the first base film 11 to the porosity of the second base film 12 is 1.05-3.
• it may be 1.05, 1.2, 1.3, 1.4, 1.51, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.4, 2.5, 2.71, 2.8, or 3, or a range formed by any two of the aforementioned values, such as 1.05-2.2, 1.2-1.51, 1.3-1.8, 1.6-2.1, 1.7-2.2, 2.1-3, etc.
• the ratio of the porosity of the first base film 11 to the porosity of the second base film 12 is 1.1-1.5.
• the first base film exhibits higher porosity, providing better air permeability, while the second base film has lower porosity, delivering higher strength to provide a support function.
• the lamination of the first base film and the second base film can improve the reliability and cycling performance of the secondary battery.
• the ratio of the porosity of the first base film to the porosity of the second base film is 1.1-1.5, the air permeability and the supporting performance of the separator can be further balanced, thereby further improving the reliability and the cycling performance of the secondary battery.
• the porosity of the first base film 11 is 30%-80%.
• it may be 30%, 35%, 38%, 40%, 50%, 55%, 60%, 70%, 75%, or 80%, or a range formed by any two of the aforementioned values, such as 30%-40%, 35%-50%, 50%-70%, 75%-80%, etc.
• the porosity of the first base film 11 is 50%-75%.
• the porosity of the second base film 12 is 30%-70%.
• it may be 30%, 35%, 40%, 45%, 50%, 60%, 65%, or 70%, or a range formed by any two of the aforementioned values, such as 30%-40%, 35%-45%, 50%-60%, 65%-70%, etc.
• the porosity of the second base film 12 is 40%-50%.
• the first base film When the porosity of the first base film is 30%-80% and/or the porosity of the second base film is 30%-70%, the first base film exhibits higher porosity with a larger average fiber filament diameter, providing better air permeability, while the second base film has lower porosity with a smaller average fiber diameter, delivering higher strength to provide a support function.
• the lamination of the first base film and the second base film can further improve the reliability and cycling performance of the secondary battery.
• the porosity of the first base film is 50%-75% and/or the porosity of the second base film is 40%-50%, the air permeability and the supporting performance of the separator can be further balanced, thereby further improving the reliability and the cycling performance of the secondary battery.
• the porosity of the separator or substrate has a meaning well-known in the art and can be tested using known devices and methods.
• the test can be performed with reference to GB/T 24586-2009 .
• the test method is as follows: punch the separator or substrate into small round sheet samples with a diameter of 14 mm, measure the thickness, and calculate the apparent volume V1 of the separator or substrate according to the cylindrical volume calculation formula; and with reference to GB/T 24586-2009 , with inert gas such as helium or nitrogen as the medium and through the gas displacement method, measure the true volume V2 of the separator or substrate using a true density tester.
• the porosity of the separator or substrate (V1-V2)/V1 ⁇ 100%.
• the testing instrument may be an AccuPyc II 1340 fully automatic true density tester from Micromeritics Corporation of the United States.
• the first base film 11 and the second base film 12 can be directly laminated by means of hot pressing.
• the hot pressing temperature is in the range of 20°C-50°C.
• an interlayer 13 may also be disposed between the first base film 11 and the second base film 1212, where the interlayer 13 includes a binder.
• the interlayer 13 includes a binder and filler particles.
• the binder includes one or more of polyacrylate, acrylic acid, carboxymethyl cellulose, polyvinylidene fluoride-co-trichloroethylene copolymer, polymethyl methacrylate, polyvinylpyrrolidone, polyvinyl acetate, polyethylene-co-vinyl acetate copolymer, polyethylene oxide, polyarylate, cellulose acetate, cellulose acetate butyrate, cellulose acetate propionate, polyvinylidene fluoride, polyacrylonitrile, polyvinyl alcohol, starch, hydroxypropyl cellulose, regenerated cellulose, tetrafluoroethylene, polyethylene, polypropylene, and cyanoethyl pullulan.
• carboxymethyl cellulose may be used as a thickener to adjust the viscosity of the slurry.
• the filler particles include at least one of inorganic particles, organic particles, or organic-metal framework materials.
• the inorganic particles include one or more of inorganic particles with a dielectric constant of 5 or higher, inorganic particles with ion conductivity but not storing ions, and inorganic particles capable of undergoing electrochemical reactions.
• the inorganic particles with a dielectric constant of 5 or higher may include at least one of boehmite, aluminum oxide, zinc oxide, silicon oxide, titanium oxide, zirconium oxide, barium oxide, calcium oxide, magnesium oxide, nickel oxide, tin oxide, cerium oxide, yttrium oxide, hafnium oxide, aluminum hydroxide, magnesium hydroxide, silicon carbide, boron carbide, aluminum nitride, silicon nitride, boron nitride, magnesium fluoride, calcium fluoride, barium fluoride, barium sulfate, magnesium aluminum silicate, magnesium lithium silicate, magnesium sodium silicate, bentonite, hectorite, zirconium titanate, barium titanate, Pb(Zr,Ti)O 3 (abbreviated as PZT), Pb l-m La m Zr l-n Ti n O 3 (abbreviated as PLZT, 0 ⁇ m ⁇ 1, 0 ⁇ n n
• the modification method for each inorganic particle may be chemical modification and/or physical modification.
• the chemical modification methods include coupling agent modification (e.g., using silane coupling agents, titanate coupling agents, etc.), surfactant modification, polymer grafting modification, etc.
• the physical modification methods may include mechanical dispersion, ultrasonic dispersion, high-energy treatment, etc. Through modification treatment, the agglomeration of inorganic particles can be reduced, thereby enabling the adhesive layer to have a more stable and more uniform structure.
• coupling agents, surfactants, or polymers with specific functional groups to modify the inorganic particles, it further enhances the adhesive layer's wetting and retention properties toward the electrolyte solution and improves the adhesion of the adhesive layer to the first base film and the second base film.
• the inorganic particles with ion conductivity but not storing ions may include at least one of Li 3 PO 4 , lithium titanium phosphate Li x1 Ti y1 (PO 4 ) 3 , lithium aluminum titanium phosphate Li x2 Al y2 Ti z1 (PO 4 ) 3 , (LiAlTiP) x3 O y3 -type glass, lithium lanthanum titanate Li x4 La y4 TiO 3 , lithium germanium thiophosphate Li x5 Ge y5 P z2 S w , lithium nitride Li x6 N y6 , SiS 2 -type glass Li x7 Si y7 S z3 , and P 2 S 5 -type glass Li x8 P y8 S z4 , where 0 ⁇ x1 ⁇ 2, 0 ⁇ y1 ⁇ 3, 0 ⁇ x2 ⁇ 2, 0 ⁇ y2 ⁇ 1, 0 ⁇ z1 ⁇
• the inorganic particles capable of undergoing electrochemical reactions may include at least one of lithium-containing transition metal oxides, lithium-containing phosphates, carbon-based materials, silicon-based materials, tin-based materials, and lithium titanium compounds.
• the organic particles may include one or more of polycarbonate, polythiophene, polypyridine, polystyrene, polyacrylic wax, polyethylene, polypropylene, cellulose, cellulose modifiers (e.g., carboxymethyl cellulose), melamine resin, phenolic resin, polyesters (e.g., polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate), silicone resin, polyimide, polyamide-imide, polyarylamide, polyphenylene sulfide, polysulfone, polyethersulfone, polyether ether ketone, polyaryletherketone, copolymers of butyl acrylate and ethyl methacrylate (e.g., crosslinked polymers of butyl acrylate and ethyl methacrylate).
• polycarbonate polythiophene
• polypyridine polystyrene
• polyacrylic wax polyethylene
• polypropylene e.g., polyprop
• the organic-metal framework materials may include one or more of nitrogen-containing heterocyclic ligand-based structures, organic carboxylic acid ligand-based structures, and nitrogen-oxygen mixed ligand-based structures.
• the interlayer may further include a dispersant, for example, carboxymethyl cellulose, thereby adjusting the viscosity of the interlayer slurry and improving the quality and uniformity of the interlayer.
• a dispersant for example, carboxymethyl cellulose
• the separator 10 satisfies at least one of the following (1)-(3): (1) the weight per unit area of the separator 10 is 5-20 g/m 2 , optionally 6-15 g/m 2 ; (2) the porosity of the separator 10 is 30%-55%, optionally 35%-45%; and (3) the air permeability of the separator 10 is less than 350 s/100 cc-400 s/100 cc, optionally 150 s/100 cc-300 s/100 cc.
• the separator When the separator satisfies at least one of the aforementioned features within the given ranges, the separator can be enabled to possess good heat resistance and strength, thereby improving the reliability and cycling performance of the secondary battery.
• the present application provides a secondary battery, including the separator 10 of any of the aforementioned schemes.
• the secondary battery employs the provided separator 10, the reliability of the secondary battery can be improved.
• the secondary battery further includes a positive electrode plate and a negative electrode plate, where the separator 10 is disposed between the positive electrode plate and the negative electrode plate, and the first base film 11 of the separator 10 faces the positive electrode plate.
• the positive electrode plate typically includes a positive electrode current collector and a positive electrode film layer arranged on the positive electrode current collector, where the positive electrode film layer includes a positive electrode active material.
• the positive electrode current collector may adopt conventional metal foil or a composite current collector (a composite current collector may be formed by applying a metal material onto a polymer substrate).
• a composite current collector may be formed by applying a metal material onto a polymer substrate.
• the positive electrode current collector may use aluminum foil.
• the positive electrode active material may include, but is not limited to, one or more of lithium transition metal oxides, olivine-structured lithium-containing phosphates, and their respective modified compounds.
• the lithium transition metal oxide may include, but are not limited to, one or more of lithium cobalt oxide, lithium nickel oxide, lithium manganese oxide, lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminum oxide, and modified compounds thereof.
• Examples of the olivine-structured lithium-containing phosphate may include, but are not limited to, one or more of lithium iron phosphate, composites of lithium iron phosphate and carbon, lithium manganese phosphate, composites of lithium manganese phosphate and carbon, lithium manganese iron phosphate, composites of lithium manganese iron phosphate and carbon, and modified compounds thereof. These materials are all commercially available.
• the positive electrode film layer more optionally further includes a binder, a conductive agent, and other optional additives.
• the binder may include one or more of polymerized styrene butadiene rubber (SBR), water-based acrylic resin, polyvinylidene difluoride (PVDF), polytetrafluoroethylene (PTFE), ethylene-vinyl acetate copolymer (EVA), polyacrylic acid (PAA), carboxymethyl cellulose (CMC), polyvinyl alcohol, vinylalcohol polymer (PVA), and polyvinyl butyral (PVB).
• SBR polymerized styrene butadiene rubber
• PVDF polyvinylidene difluoride
• PTFE polytetrafluoroethylene
• EVA ethylene-vinyl acetate copolymer
• PAA polyacrylic acid
• CMC carboxymethyl cellulose
• PVA vinylalcohol polymer
• PVB polyvinyl butyral
• the negative electrode plate typically includes a negative electrode current collector and a negative electrode film layer arranged on the negative electrode current collector, where the negative electrode film layer includes a negative electrode active material.
• the negative electrode current collector may adopt conventional metal foil or a composite current collector (for example, a composite current collector may be formed by applying a metal material onto a polymer substrate). As an example, the negative electrode current collector may use copper foil.
• the negative electrode active material may include, but is not limited to, one or more of artificial graphite, natural graphite, hard carbon, soft carbon, silicon-based materials, and tin-based materials.
• the silicon-based material can be selected from one or more of elemental silicon, a silicon oxide compound (e.g. silicon (II) oxide), a silicon-carbon composite, a silicon-nitrogen composite and silicon alloy.
• the tin-based material may be selected from one or more of elemental tin, a tin oxygen compound and a tin alloy. These materials are all commercially available.
• the negative electrode active material may include a silicon-based material.
• the negative electrode film layer more optionally further includes a binder, a conductive agent, and other optional additives.
• the conductive agent may be one or more of superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers.
• the binder may be one or more of styrene butadiene rubber (SBR), water-based acrylic resin, polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), ethylene-vinyl acetate copolymer (EVA), polyvinyl alcohol (PVA), and polyvinyl butyral (PVB).
• SBR styrene butadiene rubber
• PVDF polyvinylidene fluoride
• PTFE polytetrafluoroethylene
• EVA ethylene-vinyl acetate copolymer
• PVA polyvinyl alcohol
• PVB polyvinyl butyral
• additives may be thickeners and dispersants (e.g., carboxymethylcellulose sodium (CMC-Na)) and PTC thermistor materials.
• CMC-Na carboxymethylcellulose sodium
• the secondary battery may include an electrolyte solution, which functions to conduct ions between the positive and negative electrodes.
• the electrolyte may include an electrolyte salt and a solvent.
• the electrolyte salt may be one or more selected from lithium hexafluorophosphate (LiPF 6 ), lithium tetrafluoroborate (LiBF 4 ), lithium perchlorate (LiClO 4 ), lithium hexafluoroarsenate (LiAsF 6 ), lithium bis(fluorosulfonyl)imide (LiFSI), lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), lithium trifluoromethanesulfonate (LiTFS), lithium difluoro(oxalato)borate (LiDFOB), lithium bis(oxalate)borate (LiBOB), lithium difluorophosphate (LiPO2F 2 ), lithium difluoro bis(oxalato)phosphate (LiDFOP) and lithium tetrafluoro(oxalato)phosphate (LiTFOP).
• LiPF 6 lithium hexafluorophosphat
• the solvent may be selected from one or more of ethylene carbonate (EC), propylene carbonate (PC), methyl ethyl carbonate (EMC), diethyl carbonate (DEC), dimethyl carbonate (DMC), dipropyl carbonate (DPC), methyl propyl carbonate (MPC), diisopropyl carbonate (EPC), butylene carbonate (BC), fluoroethylene carbonate (FEC), methyl formate (MF), methyl acetate (MA), ethyl acetate (EA), n-propyl acetate (PA), methyl propionate (MP), ethyl propanoate (EP), n-propyl propionate (PP), methyl butyrate (MB), ethyl butyrate (EB), 1,4-butyrolactone (GBL), tetramethylene sulfone (SF), methyl sulfone (MSM), methyl ethyl sulfone (EMS), and die
• the average fiber filament diameter of the first base film with a higher melting point is greater than the average fiber filament diameter of the second base film with a lower melting point
• the smaller average fiber filament diameter of the second base film endows the second base film with abundant pore channel structures, enhancing its tolerance to physical puncture by lithium dendrites.
• the average fiber filament diameter of the first base film with a higher melting point is greater than the average fiber filament diameter of the second base film with a lower melting point, it is also possible to ensure the continuity and effectiveness of ion transport channels in the final separator, which can enable the final separator to possess both heat resistance and high strength, thereby improving the reliability of the secondary battery.
• Fig. 3 shows a secondary battery 5 with a square structure as an example.
• the secondary battery may include an outer package.
• the outer package is used to encapsulate the positive electrode plate, the negative electrode plate, and the electrolyte.
• the first base film 11 of the separator 10 faces the positive electrode plate.
• the secondary battery may be formed by assembling the positive electrode plate, the separator 10, the negative electrode plate, and the electrolyte solution.
• the positive electrode plate, the separator 10, and the negative electrode plate may be formed into an electrode assembly through winding and/or stacking processes.
• the electrode assembly is placed in the outer package, dried and then filled with the electrolyte solution, and subjected to vacuum sealing, standing, chemical formation, shaping, and other processes to obtain a battery cell.
• a plurality of battery cells may be further connected in series, in parallel, or in a mixed connection to form a battery module.
• a plurality of battery modules may be further connected in series, in parallel, or in a mixed connection to form a battery pack.
• a plurality of battery cells may directly form a battery pack.
• Fig. 5 shows a battery module 4 as an example.
• a plurality of secondary batteries 5 can be sequentially arranged along the length direction of the battery module 4.
• the plurality of secondary batteries 5 may further be fixed by fasteners.
• the battery module 4 may further include a shell having an accommodating space, in which the plurality of secondary batteries 5 is accommodated.
• the above-mentioned battery modules can further be assembled into a battery pack, and the number of battery modules contained in the battery pack can be adjusted according to the application and capacity of the battery pack.
• the battery pack 1 may include a battery box and a plurality of battery modules 4 disposed in the battery box.
• the battery box comprises an upper box body 2 and a lower box body 3, where the upper box body 2 can cover the lower box body 3 and forms an enclosed space for accommodating the battery module 4.
• the plurality of battery modules 4 may be arranged in the battery box in any manner.
• the electrical apparatus may be a mobile phone, a tablet, a laptop.
• the electrical apparatus is generally required to be thin and light, and may use a battery cell as a power source.
• SuperP conductive agent carbon black
• SBR binder styrene-butadiene rubber
• CMC-Na sodium carboxymethyl cellulose
• the separator is the aforementioned separator 1 prepared above.
• the melting point of the second base film is lower than that of the first base film, and the average fiber filament diameter in the first base film is greater than that in the second base film.

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• 2023
  • 2023-03-17 EP EP23927913.6A patent/EP4601104A4/de active Pending
  • 2023-03-17 JP JP2025525137A patent/JP2025536583A/ja active Pending
  • 2023-03-17 CN CN202380045990.8A patent/CN119343826A/zh active Pending
  • 2023-03-17 KR KR1020257014558A patent/KR20250070117A/ko active Pending
  • 2023-03-17 WO PCT/CN2023/082337 patent/WO2024192594A1/zh not_active Ceased
• 2025
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